In a move that took many music and celebrity gossip fans by surprise, Katy Perry penned an open Instagram Stories letter to long-time rival Taylor Swift on Tuesday, just hours before the latter kicked off her "Reputation" stadium tour.

Perry and Swift, of course, have been engaged in a passive aggressive rivalry for years.

Neither has spoken much about it directly, but each has seemingly referenced the other in songs and in various interviews.

The beef goes back about half a decade and was allegedly ignited due to Perry's stealing of a couple Swift backup dancers for one of her own international tours.

"She did something so horrible. I was like, 'Oh, we're just straight-up enemies.' And it wasn't even about a guy!" Swift told Rolling Stone of the subject of the track "Bad Blood" in 2014, never actually saying Perry's name.

Added Taylor in this revealing exchange:

"It had to do with business. She basically tried to sabotage an entire arena tour. She tried to hire a bunch of people out from under... So now I have to avoid her. It's awkward, and I don't like it."

We've loved it, however.

The feud has been a blast to speculate over and cover.

But now it's come to an end?

Evidently so.

"Hey Old Friend - I’ve been doing some reflecting on past miscommunications and hurt feelings between us,” Perry wrote in a letter we can see parts of via a Swift Instagram video.

The letter is partially obscured, but it also appears to say Katy is “deeply sorry” and wants to “clear the air.”

Included along with the letter, which was actually mailed to Swift, is a literal olive branch.

Panning over the gift in her dressing room in response, Swift says on social media:

“I just got to my dressing room and found this actual olive branch. This means so much to me.”

This is quite the departure for Perry, who tried to use her negative back-and-forth with Swift to promote her last album.

“Maybe I don’t agree with everything she does and she doesn’t agree with everything I do, but I just really, truly want to come together in a place of love and forgiveness and understanding and compassion,” the singer said.

Fair enough.

We're willing to believe Perry is being sincere and we're now hoping to see these two take the stage peacefully together at some point.

That would be fun to see, wouldn't it?

Heck, perhaps an album of duets?!?

Okay, maybe now we're aiming too high.

But in a polarizing country, where it seems like no one can get along, it's nice to see Perry and Swift setting an example for the rest of us to follow.